1. Field of the Invention
The present invention relates to a system for filling containers with liquid or viscous materials. More particularly this invention concerns a machine for filling bottles with milk, juice, soda, or the like.
2. Background of the Invention
In order to fill containers such as bottles with liquids such as juice or dairy products of highly liquid or somewhat viscous consistency it is known to use a machine such as described in German patent document 196 42 987 of P. Gustafsson and P. Fontanazzi. The bottles are held in basket-like seats in holders that are mounted on a chain that is passed through various machines that sterilize, fill, seal, and cap the bottles. The filling machine has a nozzle that aligns vertically with the bottle mouths as they stop in the filling station to squirt a quantity of the liquid down into the stationary bottles sitting underneath the nozzles in the seats of the holders.
Such a system is relatively effective with many liquids, in particular somewhat viscous ones. When used, however, with liquids like milk that tend to foam when agitated, they are ineffective, causing a body of foam to rise up in the bottles as they are filled, overflowing the tops and making it impossible to hygienically seal the containers.
Accordingly German patent document 2,922,308 of G. Haug and A. Zehnder describes a system where dip tubes are provided that are displaced down into a position with their lower ends near the bottoms of the bottles in the filling station, then as they are raised the liquid is emitted from the tube lower ends, resulting in smooth filling with minimal generation of foam. This arrangement is fairly difficult to control in that the telescoping dip tubes tend to leak and are hard to position perfectly. If the alignment of a bottle with the respective tube is not perfect, the liquid is spilled or the machine is shut down.
German patent document 2,509,611 of G. Hahn and T. Schneider describes an apparatus for filling small cups with liquid. Once the holder chain stops in the filling/capping station, the cups are raised out of the holder into engagement with the filling/capping device. While this system is relatively effective for short wide-mouth cups, it is not applicable to tall small-mouth bottles because of the difficulty of accurately aligning the small bottle mouths with the filling nozzles or tubes.
It is therefore an object of the present invention to provide an improved apparatus for filling bottles with liquid.
Another object is the provision of such an improved apparatus for filling bottles with liquid which overcomes the above-given disadvantages, that is which allows even tall small-mouth bottles to be filled with a highly foamable liquid with no significant chance of spillage or generation of foam.
A bottling apparatus has according to the invention a frame and an endless conveyor element on the frame, having a horizontal working stretch extending in a transport direction through a filling station, and carrying a plurality of holder plates each formed with a row of seats adapted to fit snugly around necks of bottles. Couplings releasably secure the holder plates to the conveyor element with the holder plates spaced in the transport direction along the working stretch and the rows extending transverse to the transport direction. Bottles are loaded into the seats upstream of the filling station with mouths of the bottles open upward and the bottles hanging by their necks from the holder plates and are removed from the seats downstream of the filling station. A drive advances the conveyor element stepwise in the transport direction in the working stretch and arrests each of the holder plates in the filling station with the bottles in its seats aligned with the fill tubes. A plurality of stationary upright fill tubes in the filling station above the working stretch are aligned with the seats of the holder plate in the filling station. The plates are lifted in the filling station off the conveyor element to engage the fill tubes down into the respective bottles so they can be filled through the tubes.
Thus with this system the bottles are held by their necks and are raised by the holders up to insert the fill tubes into them. In this manner it is possible even to align a relatively small bottle mouth perfectly with a filler tube and fill a relatively large bottle with liquid while generating no foam. The holders are lowered synchronously as liquid is introduced into the bottles to keep the liquid level at a constant position relative to the filler tubes. Such an arrangement can work with tall or short bottles easily with the same holder plates.
The conveyor element has in the working stretch an upper surface and the plates have in the working stretches lower surfaces resting on the conveyor element upper surface. The couplings each have according to the invention a vertically extending pin projecting from one of the surfaces and a coupling hole in the other of the surfaces receiving the respective pin. More particularly the pins project and taper upward from the upper conveyor-element surface and the coupling holes are formed in the plates. In addition the conveyor element is formed by a pair of horizontally spaced endless chains each having a succession of the pins. The plates are each transversely elongated and have ends each formed with a respective one of the coupling holes.
Each plate in accordance with the invention is formed by a pair of separable subplates each formed with a pair of transversely spaced coupling holes. Confronting edges of the subplates have cutouts together forming the seats, and the subplates are pivoted apart at upstream and downstream ends of the working stretch to allow bottles to be loaded in and taken out.
A stationary guide pin projecting downward in the filling station has a free lower end spaced immediately above the plate in the filling station in the lower position thereof. The plates are each formed with a vertically throughgoing guide hole aligned with the guide pin so that when the plate is raised from the lower position the guide pin fits into the respective guide hole. This prevents the plates from shifting horizontally after being lifted off the coupling pins on the conveyor element. To ensure smooth vertical movement of the plates as they are raised and lowered a hold-down element engages down against an upper face of the holder plate in the filling station and is raised with the plate on movement of same from the lower position to the upper position, normally clamping the plate against a raised guide-rail section as described below.
In accordance with the invention at least one horizontal guide rail extending along the working stretch through the filling station has an upper surface on which the holder plates slide as they advance in the direction. This rail has a low-friction upper surface engaging the holder plates in the working stretch. The guide rail further has in the filling station a section displaceable vertically relative to the rest of the rail. The lifting means is an actuator connected to the rail section. More particularly there are two such guide rails extending parallel to each other spaced apart transversely to the direction and each having a respective such section. A transverse beam extends between and is fixed to the two sections. The actuator includes an electric motor mounted on the frame, a single output shaft extending horizontally transverse to the direction and driven by the motor, and respective linear drives connected between ends of the shaft and ends of the transverse beam. The linear drives are each a chain or belt drive having an upper end connected to the end of the output shaft and a chain or belt connected to the respective end of the transverse beam.
To prevent overly fast movement of the bottles, especially when they are full, a damping element connected to the frame and to the beam damps vertical movement of the beam. This damping element is a pneumatic cylinder.